At present, various chemicals exhibiting actions such as bleaching, sterilization and disinfection are known, and particularly hypochlorites such as sodium hypochlorite are used as chlorine type sterilizers, and hydrogen peroxide and sodium percarbonate and sodium perborate generating hydrogen peroxide in water are mainly used as oxygen type sterilizers. However, these sterilizers have various problems; for example, hypochlorites have problems such as corrosion of metal etc. and generation of chlorine gas by misuse, and hydrogen peroxide has problems such as use at high concentration and necessity for long-time contact in order to achieve a sterilizing effect at high degree. When hydrogen peroxide is used, measures to increase a sterilizing effect by using it in combination with an activator to generate an organic peracid at use have been taken to solve these problems. As such a sterilizer composition, JP-A 6-305920 discloses a sterilizer composition containing an inorganic peroxide, an organic acid incomplete ester with a polyhydric alcohol, and an alkaline earth metal salt. For a method of applying an organic peracid as a sterilizer, mention is made of JP-A (W) 8-500843 and JP-A 8-311495. JP-A 5-25497 proposes a method of improving a bleaching effect by adjusting pH in a system of generating an organic peracid. WO-A 01/70030 discloses that a composition containing hydrogen peroxide, a carboxylic acid, and a percarboxylic acid in a specific ratio to the hydrogen peroxide exhibits an antibacterial action on spores and spore-forming microorganisms.
An organic peracid, for example, peracetic acid is produced continuously by reacting hydrogen peroxide with acetic acid under acidic conditions to give an equilibrated mixture containing peracetic acid, acetic acid, hydrogen peroxide and water. Alternatively, peracetic acid can be produced by partial oxidation of acetaldehyde in a gaseous phase or by oxidizing acetaldehyde in the presence of a catalyst to form an intermediate acetaldehyde monoperacetate and then decomposing it in a solvent. JP-A 52-25034 and JP-A 52-25011 disclose a concentrate suitable for sterilization, which contains peracetic acid or acetic acid, hydrogen peroxide, water, etc.